Oxford LHCb Why flavour physics matters Status of LHCb and Oxford group RICH activities Physics activities Summary and Outlook Jim Libby, PP Open Day, 5/10/07

5/10/2006 PP Open Day Flavour physics Flavour physics has been an essential to the construction of Standard Model: GIM mechanism → charm CP Violation → 3 generations B mixing → heavy top All surprises that predated ‘direct’ discovery! We may assume same story will continue! Precise measurements  nature of new physics at TeV scale and beyond. In B physics goal is to look for new sources of CP violation, or deviations from SM in very rare CP conserving processes, eg. BR(B s →μμ)

5/10/2006 PP Open Day LHCb in a slide Muon Detector Tracking stations Trigger Tracking proton beam interaction region Forward geometry:  bb/2 fb -1  both B hadrons in acceptance for tagging  excellent proper time resolution RICHs for hadron ID Hardware and software trigger for B-physics Ready for LHC t 0 Interaction point

5/10/2006 PP Open Day LHCb Oxford Faculty: N. Harnew (RICH coordinator) & G. Wilkinson (CP working group convenor) Dept. Lecturer: J. Libby Royal Soc Fellow: Malcolm John Postdocs: R. Muresan & P. Spradlin Students: A. Powell, S. Brisbane, L. Martin, F. Xing, Philip Hunt and Chris Thomas (joint with RAL) Electronics, Systems and Software Engineers: I. McArthur, P. Sullivan, S. Topp-Jorgensen RICH 1 Mechanics : T. Handford, B. Ottewell, R. Senanayake Grid programmers: A. Soroko 13 physicists and engineers 6 students

5/10/2006 PP Open Day Status of the L0 electronics Oxford’s responsibility is the front-end electronics for the RICH detectors Hybrid Photo-Detectors (HPDs) detect the Cherenkov radiation by detecting photoelectrons on a 32×32 pixel detector encapsulated within the detector readout pixel chip silicon detector Schematic of a HPD section 72 mm

5/10/2006 PP Open Day Level-0 Production & DAQ status 300 boards have been produced and tested in Oxford  242 boards required to equip both RICHes  Project finished successfully Commissioning is in progress – all RICH2 photon detectors have been successfully read out Final Level-0 experimental control system (ECS) is very well advanced at CERN Sean Brisbane Neville Harnew Jim Libby Phil Sullivan Stig Topp Jorgensen PIXEL anodes Level-0 board Kaptons

5/10/2006 PP Open Day HPD column mounting at CERN Sean Brisbane Andrew Powell Phil Sullivan All RICH-1 and RICH-2 ladders are now fully equipped with HPDs and Level-0 boards HPDs L0 boards RICH 2 RICH 1

5/10/2006 PP Open Day Testbeam evaluation of 48 HPDs in 60 GeV/c beam with C 4 F 10 radiator. 6 L0 Readout in Action (Beam single particles with composition 80% , 10% e, 7% K, 3% p)

5/10/2006 PP Open Day RICH1 mechanics Oxford has extensive involvement in RICH1 mechanics project, vital to the collaboration for delivering on time-critical items. Work in collaboration with ICSTM. Oxford produced final design and supervised construction of the RICH1 gas enclosure. This is now installed. Designed mechanical support and lifting rig for gas enclosure. Designed and constructed mirror installation & storage boxes Designed and supervised fabrication of upper and lower HPD mounting and rail system. Matthew Brock, Charlie Evans Wing Lau, Brian Ottewell Tony Handford, Rohan Senanayake, Mike Tacon and the workshop team

5/10/2006 PP Open Day Oxford and LHCb Physics Oxford has had leading involvement in physics studies of LHCb flag-ship measurements since start of collaboration, and this continues. Developed new strategies to extend ‘physics-reach’ of experiment. At present, tightly-focused and intensive programme in two key areas: Re   1 Im 1) Precise measurement of the unitarity triangle γ (LHCb’s raison d’etre ?) 2) Studies of charm mixing and search for CP violation in the D system. [Libby, Harnew, Wilkinson, Powell, Brisbane, Martin] [Wilkinson, Spradlin, Xing, Muresan]

5/10/2006 PP Open Day → f 2 + Oxford LHCb and the UT Angle γ Best way (statistically precise and theoretically clean) to measure γ is through ‘B→DK’ decays. Compare rates or kinematical distributions between B + and B - for cases where f is a final state common to D and Dbar. KK ππ K s ππ Kπππ KKππ Kππ 0 Interference term picks out γ γ is essentially the CP violating phase in b→u transitions. It is very badly known (σ ~ 30 0 ). A precise measurement of γ is the next big challenge in flavour physics. Oxford LHCb is leading this work. We estimate combined precision of 1-2 o possible at LHCb ! γ

5/10/2006 PP Open Day Summary and Outlook Oxford efforts have been central to getting LHCb RICH system built and ready for data-taking LHCb physics programme is of highest scientific importance. All measurements will begin in earnest as soon as machine and detector is commissioned. Oxford in pole position to lead several of most important analyses, in particular γ measurement and charm studies.